Thursday, December 27, 2007

-is a region of space i which the gravitational field is so powerful that nothing can escape after having fallen past the event horizon-the name comes from the fact that even electromagnetic radiation (e.g. light) is unable to escape, rendering the interior invisible-black holes can be detected if they interact with matter outside the event horizon, for example by drawing in gas from an orbiting star-gas spirals inward, heating up to very high temperatures and emitting large amounts of radiation in the process